The definition of magma

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I was talking to a geologist the other day, and he told me that magma is a generic term for molten rock. See, for example, Mineralogy by Dexter Perkins, pg. 32. It's a standard 200-level college textbook that uses this definition. I had learned when younger that magma is like lava except under the ground (essentially what this page currently states) and was surprised to hear the geologist's alternate definition. Are there conflicting definitions of magma? Obviously so. Is there widespread use of the "magma means molten rock" definition? I don't know, but if so, we might want to add it to this page. --Douglaspperkins (talk) 13:20, 9 September 2015 (UTC)Reply

All the sources I read still make the distinction between lava and magma, even though it's like the difference between Tylenol and acetaminophen. --NoNonsenseHumJock (talk) 16:33, 2 September 2021 (UTC)Reply
I'm a bit concerned about this. Magma is not just molten rock; it is a mixture of molten rock, solid crystals, and dissolved gases. --Kent G. Budge (talk) 16:59, 2 September 2021 (UTC)Reply

Consolidation of Magma, Lava, and Volcano

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All three articles have considerable material on composition and properties of melts. I am working to centralize this discussion in this article, which seems like the most natural place for it. That discussion can then be referenced in the other articles, reducing duplication considerably. --Kent G. Budge (talk) 17:42, 8 February 2021 (UTC)Reply

Definitely in favor of consolidating Lava and Magma into a single page, probably by repurposing Molten rock. There's a huge amount of duplication between the two pages. Not so sure about Volcano. --NoNonsenseHumJock (talk) 16:33, 2 September 2021 (UTC)Reply
There was a discussion of this at the WP:Geology page many months ago, now (alas) archived. My own preference would be to let Volcano focus on volcanic landforms, Lava emphasize lava flows, and Magma emphasize the physical substance. However, some editors see no problem with duplication of material on closely related topics. I would very much dislike consolidating onto Molten rock, since magma and lava are much more than molten rock -- they also contain solid crystals and dissolved gases, which are very important in determining their properties. I agree, though, that the distinction between lava and magma is slightly arbitrary; lava is magma that has reached the surface and degassed, though in fact it hasn't entirely degassed; what is important about lava that is distinct from magma really is lava flows. --Kent G. Budge (talk) 17:05, 2 September 2021 (UTC)Reply